1. Field of the Invention
The present invention relates to an antenna for receiving and/or transmitting electromagnetic waves, comprising an array of antenna elements including at least one longitudinal row of antenna elements located at a distance from each other and parasitic elements located in the vicinity of the gaps there-between.
2. Description of the Related Art
Such antennas are used, inter alia, for the transfer of microwave carriers in telecommunication systems, in particular in base stations for cellular mobile telephones.
A broadband microstrip array antenna is described in GB-A-2266809 (Aerospatiale Societe Nationale Industrielle). In each longitudinal row of active antenna elements, in the form of rectangular patches, there are interposed parasitic elements in the form of patches which almost fill out the respective gap between adjacent active antenna elements. The slots between the adjacent active and passive patches are relatively small, whereby a strong coupling will occur so that the passive or parasitic elements form integral parts of the antenna and serve to broaden the effective bandwidth thereof.